How to Write the T-SQL Code for Joins

A "join" statement is a part of Transact-Structured Query Language, or T-SQL, that retrieves information from a Microsoft SQL Server. A "join" statement links two tables together. Instead of querying two tables separately, you use the "join" statement to connect the two tables and use one query. This is more convenient and uses fewer resources on the database server. The "join" statement integrates with the T-SQL "select" statement.

Instructions

1. Click the Windows "Start" button and select "All Programs." Click "Microsoft SQL Server" and click the "Microsoft SQL Server Management Studio" shortcut to open the SQL programming software.

2. Click the "New Query" button in the Management Studio toolbar at the top of the window. This opens a programming editor where you code the "select" and "join" statements.

3. Type the T-SQL statement. In this example, a customer table is joined to an orders table, so you can retrieve a customer and all related orders. Type the following code into the editor:

   select * from customer

   join orders on orders.customerid=customer.customerid

   In this example, the join statement joins the customer and orders table on the "customerid." Records returned are customers and their associated orders.

4. Press "F5" to execute the code. You can also click the "Run" button in the Management Studio toolbar. The results for the query are shown at the bottom of the window.

References

• Microsoft: Select Syntax